Machine for the coating of webs of material



April l5, 1952 Filed NOV. 25, 1949 A. R. 'rRlsT 2,593,074

MACHINE FOR THE COATING OF WEBS OF MATERIAL 5 Sheets-Sheet 1 April l5, 1952 A. R. TRlsT MACHINE FOR THE COATING OF' WEBS 0F MATERIAL Filed Nov. 25, 1949 5 Sheets-Sheet 2 F/G./O. F/G.9.

April l5, 1952 A. R.. TRlsT 2,593,074

MACHINE FOR THE coATING oF WEBS oFMATERIAL Filed Nov. 25, 1949 s sheets-sheet 's the description;

Patented Apr. 15, 1952 MACHINE Fon THE ooA'rING oF WEBsoF MATERIAL Arthur Ronald Trist, st. Catherines', ontario,

Canada f j Application November 25, 1949, Serial No. 129,289 In Great Britain December 93,1949. r l

, 1 'I'he invention relates to improvements in machines fork the coating ofwebs of material and has particular'l reference to coating machines in which a web of material is coated with a composition over a given width and passed between a stationary trailing blade and a resilient moving bed the bladev and bed being adjusted relatively to one another to produce a continuous layer of the coating substance-on the web from a fountain formed by the surface of the web supported bythe bed, and the surface of the blade,-the width of the coated surface being controlled by dykes that-are adjustably mounted on the fountain and have 4surfaces 'f in close proximity ywith or even touching the moving web. l

.Theinvention has for its object to provide means whereby irregular wear of theV blade is avoided, the'body of the coating applied to the web of material is maintained of even thickness andthe thickness of each margin of the coating is equal to or less than that. of the body of the `coating to avoid objectionable stressing or straining of the margin of the web of coated material during re-reeling.

l This invention consists in a machine f or the coating of webs of material comprising a resilient moving bed, supporting the web of material, a fountain for the coatingv composition having a floor at its lower part .to `form a stock for a stationaryelastic trailing .blade for controlling the application of the composition and dykes for limiting the width ofthe fountain for the coating composition and is characterisedv in that the length of the blade is lessV than the distance between the outer. edges of the dykes and that Ythe corners where the blade, the facing surfaces of the dykes and the surface of the webmeet are sealed against liquid leakage by angular elements each of which rests on the floor of the fountain,

,has .a surface adjacent to a facing wall of a dyke and has a metering surface arranged to be adjacentto the `web but not in contact therewith.

Inv the drawings: e Figure l is a fragmentary. perspective elevation of part o f a coating machine of the kind to which this inventionrelatfes and which is Ypertinent to `Figure 2 is a fragmentary exaggerated side elevation of a worn blade;

Figure 3 is a diagrammatic plan view of an, 1n-

Figure 4, is afdiagrammatic plan view Vof an arrangement having` a blade the length offwhichl ftector; A

vclaims. (clins-4cmi f yf .is less than the distance 4between the outer edges ofthe dykes; 'i l .l

Figure 5 is a diagrammatic plan vviewiofan arrangement having a blade the lengthoflwhich is less than the distance between -the facing sur faces of the dykes; C l

Figure 6 is a side elevation' f one form 'of pro- Figure 7 is an end elevation Figure 6E l i Figure 8 is la plan'view of Figure 6; Figure 9 is a side elevation of-another formof protector;v

Figure lois an end elevation ofFigure 9; f Figure 11 is a plan View of Figure 9; f l 4 Figure 12` is a fragmentary plan view ofa coating machine showing `a method rof lmounting a protector of the kind shown in Figures 6, 7 and 8; Figure 13 isa fragmentary'sideelevation' of a coating machine partly in vsectionA to show a methodof mountingv a protector of the kind shown in Figures 9, 10 and 11; 1 l

Figure 14 is a cross section through '-a margin of a coated web drawn to an exaggerated scale; Figure 15 isl a side elevation of `a pneumatic protector and Figure 16'is a side elevation of an inflatable member to be interposed between the under side 'of a protector and the oor of the fountain..

When the movingbed is a resilient cylinder or roller I covered with resilient material i.,e.` a layer Ill of india `rubberfas shown in Figurexl Aand the coating composition is abrasive, the edge 2 of the very thin steel blade `3` e. g. .about..one hundredth of an inch in thickness, is worn .away

l irregularly somewhat as shown to an exaggerated extent in'Figure'Z. f ".lhe end parts 4, 4 of the blade 3, protectedby and extending beyond the dykes 5, 5 (shown `dotted in Figure 2) ,are affected to a very-much less extent (if at all) than the operativepart B between the,V dykes 5, 5whi1st the partsl, 1

lof theedge immediately within the dykes,4 5, 5 vare affected to a greater extent than.the part 6 owing to the Vseverity of l the scouring action vof the `streamof composition produced in the two outer corners .of the fountain at the parts .of the surfaceof the web to contact V'with the blade 3 and a'dyke 5. j,

'-The result of the above described. actions Vquickly. renders the edge 2 of the blade .3 useless such an extent that the edge 2 buckles (as crudely shown in Figure 3) so that the thickness of the coating III varies across the width and the coated material is useless, and on the other hand, if to avoid buckling the length of the blade 3 is made less than the distance between the facing surfaces 5I, 5I of the dykes 5, 5 the leakage through the gaps 8, 8 between the ends of the blade 3 and the facing surfaces 5I, 5I of the dykes 5, 5 causes a thickening of the margins II2, I|2 of the coating III (as shown to exaggerated degrees in Figure 5) that in practice prevents the coated material from being rereeled without unduly stretching the margins of the web with the result that when the coated web is re-reeled, the reel is not cylindrical.

The difficulties explained above can be avoided if the length of the blade 3 is made less than the distance between the outer edges 52, 52 of the dykes 5, 5 to expose a part of the surface 53 on each dyke 5 to such an extent that the margins of the coating III are smoothed or metered to prevent the undesirable thickening II2 asshown in Figure 14.

As shown in Figure l the length of the blade 3 is less than the distance between the outer edges 52, 52 of a pair of dykes 5, 5 but is more than the distance between the facing surfaces 5I, 5I of av pair of dykes 5, 5 whilst as shown in Figure 5 the length o f the blade 3 is less than the distance between the facing surfaces 5I, 5I of a pair of dykes 5, 5 thus leaving the gaps 8, 8 between the ends of the blade 3 and the facing surfaces 5 I, 5| of the dykes 5, 5.

In the first alternative the deflection of the ends of the blade 3 incidental to the movement of the web II would cause leakage at the corner 9 where the surface of the web II, the blade 3 and the surfaces 5|, 5| of the pair of dykes 5, 5 meet whilst in the other alternative the unavoidable gaps 8, 8 also would cause leakageV at the corners 9, 9 referred to.

In both these alternative arrangements leakage is obviated by lling up the corners 9, 9 with angular elements or protectors that act as throttles and also act to deflect the streams of composition, that by abrasive action produce the excessively worn parts 1, 'I of the blade 3, harmlessly into the fountain. Y

The deection of the ends of the blade 3 is `due to the pressure exerted at those points by the coating composition that is crowded endwise by the movement of the web II so thatin the first alternative the protectors by throttling the flow of composition tend to reduce the deflection and thus reduce the leakage to a quantity that can be spread, by-the parts of the surfaces 53, 53 of the dykes 5, 5 that extend Ibeyond the ends of the blade 3, evenly on the web II without. surplus web, Ill :asain-,wtIiQutsur-nlus.-,

Each protector consists of a block I2 of any material, e. g. metal, rubber (natural or synthetic) or a synthetic composition, that is not deleteriously affected by any of the oils or solvents contained in the coating composition that may be of the kind that is not water-wetting and has an obliquely curved face I3, i. e. a curved face that approaches the web II on the roller I, indicated by a chain line in Figures 6 and 9, obliquely; as shown in Figure 'I the obliquely curved face I3 is quasitriangular and as shown in Figure l0 the face I3 is substantially rectangular.

The shape of the remainder of the block I2 as a whole has to meet certain requirements, that is to say, there must be a somewhat flat surface I4 that can .be arranged adjacent to a vertical facing wall 5I'of a dyke 5 and a lower surface I5 -proled to fit the upper surface of the floor 20 of the fountain and the upper surface of the scraper blade 3 when the machine is at rest.

Generally the blocks I2, I2 are wholly submerged in the coating composition in the fountain, although this is not strictly essential, with the curved faces I3, I3 adjacent to the web I I on the roller I but oblique thereto, that is to say, with the tips I2I, I2I of the blocks I2, I2 located in the corners 9, 9, at about one hundredth of an inch away from the surface of the web II (when of paper) on the roller I whilst the more remote part |22 of the block I2 is about one ftieth part of an inch away from the surface of the web II (when of paper) .but these distances are not definite as they depend on the nature of the web I I, the speed of movement ofthe web I I and the character of the emulsion. In no circumstances in any partof a block I2 in contact with the surface of the web I I.

The adjustment of the blocks I2, I2 on the dykes 5, 5 as shown in Figures 6, 7, 8 and l2 is simple but apt to be somewhat insufficient because the obliquity of the face I3 is more or less xed.` In this arrangement each block I2 is mounted on a stud 2| that passes through a slotted hole 22 in a dyke 5 and is provided with a nut 23 by which the block I2 can be locked in adjusted position.

The stud, 2| is embraced by the eye 24 of the screwed stem 25 that passes through the back wall 20| of the fountain and is tted with a nut 26 that is restrained from endwise movement by the back wall 20| of the fountain and the bridle 21 to enable the block I2 to be advanced and withdrawn fromv the surface of the roller I with micrometric exactitude, a liquidtight joint between the surface I5 and floor 20 being maintained by the sole I5I of flexible material e. g, india rubber, that is mounted, on the under side of the block I2 and profiled at I5 to conform with the surface of the floor 2|).

The arrangement shown in Figure 13 provides for greater universality of adjustments, each block I2 being mounted on the end of a stalk or stem 30 that is a loose nt in the hole 3| of the angle bracket 32 mounted on the outer surface 52 of a dyke 5 :by welding or by screws 54.

The upper end 33 of each stem 30, thatV passes through a hole 3|, is screw threaded and fitted with upper and lower nger nuts 34 and 35 respectively to enable exact adjustments of the block relative to the surface 5I and on the iloor 20 to be made and', to provide fora small angular adjustment of the stem 30 spherical washer assemblies 36, 36 are located between the finger nuts 34 and. 35 and the. bracket 3,2.

Withl the above; adjustments; it willbe seenthat 4a block I2 can be advanced towards and withdrawn from the surface of the web on the roller YI sufficient distances to effect adjustment whilst .the machine is in operation and that if the block I2 is tilted slightly on the upper. surface of the floor 20 of the 'fountain there is no liquid leakage because the block I2 has a sole I5I of flexible material that is sufficiently soft for the accommodation likely to be required.

The obliquity of the face I3 ofeach block I2 relatively to the surface of the web II andthe floor 20 of the fountain is so proportioned that 'on the one hand the surplus coating composition is diverted or the volume throttled and on the other hand just suiclent coating composition at a proper velocity to providethe'required width ornatural spread of coatingfil I I on the' web -II bya dyke 5, is induced into the gap between the oblique face I3 and the surface ofthe web" I I and evenly distributed by the travel of the webV II relatively to the blade 3 and. dykes 5,5.

As previously explained the lower part or sur- `face I5 of each of the blocks I2 is profiled to con- `form with the oor 20 of the fountain, that acts .as a stockfor the blade 3, and with the upper surface of the blade 3 when the machine is at rest and usually has asoft packing layer I5I to prevent leakage whilst the surface I4, is close to or in contact with a' facing surface 5I of a dyke 5, so that any gaps e.g. the gaps 8, 8 between the 2) is avoided with the result that the blade -3 can be advanced from time to time to compensate for wear until it becomes too narrow to` be held in the stock.

I claim: l. Means for controlling the leakage of liquid from the ends of the fountain for the coating Vcomposition in a coating machine havinga resilient moving bed supporting the web of material resting onthe floor'of the fountain adjacent to 'the yfacing surface of each dyke and a meteringsurface on the angular element adjacent to the web but not in contact therewith.

` 2. Means for controlling the leakage oruquiu ends of the blade 3 and the facing surfaces of the pair of dykes 5, 5 or the gaps produced by deflection of the blade 3 from the surface I5 when the machine is in operation, are effectively sealed, the blade 3 being allowed to expand longitudinally without restraint so as to avoid any cause likely to buckle the edge 2.

In certain cases it is advisable to use a more developed form of seal between the surfaces I5 and floor 20 and to this end the block I2 may be formed with a cavity |23 open to the under surface as shown in Figure 15 to enable the sole I5| of flexible material to be distended slightly by pneumatic pressure applied through the automobile tire valve |24 and stem 30|, that is in the form of a tube in this case, by a tire inflator e. g. |25.

When considerable air pressure is found to be necessary the sole I5I may be formed as an inflatable member |52 of flexible material having a lower face |53 to conform to the floor 2|) and blade 3 and an upper face |54 to conform to the under side of the block I 2 to which it may be attached.

The provision of means by which the pressure of the sole on the floor of the fountain can be varied within considerable limits enables more accurate adjustment of the protectors to be effected as the contact pressure on the floor 20 ltemporarily can be reduced Whilst the block I2 is adjusted and tilted to get the best effect and then the pressure can be increased to obtain a large area seal free from disturbing forces.

As the blade 3 can expand longitudinally without constraint between the facing surfaces 5|, 5| of the dykes 5, 5 as shown in Figure 5 or over the surfaces 53, 53 of the dykes 5, 5 as shown in Figure 4 and, owing to the blocks I2, I2 the edge 2 of the blade 3 is aifected equally by the abrasive action .of the coating composition, leakage is avoided, the proper width of coating I II is evenly applied to the web II, and the streams of composition at the dykes 5, 5 are diverted so that the margins II2, ||2 of the coating III are not thickened and the undue wear at 1, 'I (see Figure from the ends of the fountain'for the coating composition in a coating machine having 4av resilient moving bed supporting 'the web of material to be coated, a iioor for the lower part ofthe fountain to form a stock for a stationary elastic trailing blade and dykes for limiting the width ofthe fountain, comprising a stationary elastic trailing blade of less 'length than the distance between the outer edges of the dykes mounted on the floor of the fountain, an angular element resting on the floor of the fountain adjacent to the facing surface of each dyke. a cavity in the underside of each element, a layer of exible material attached to the underside of each element to seal the cavity, a conduit for admitting air under Ypressure into the cavity to distend the iiexible material into jointing coaction with the floor, and a metering surface on the angular element adjacent to the web but not in contact therewith.

3. Means for controlling the leakage of liquid from the ends of the fountain for the coating composition in a coating machine having a resilient moving bed supporting the web of material to be coated, a floor for the lower part of the fountain to form a stock for a stationary elastic trailing blade and dykes for limiting the width of the fountain, comprising a stationary elastic trailing blade of less length than the'distance between the outer edges of the dykes mounted on the oor of the fountain, an angular element resting on the floor of the fountain and slidingly mounted on the facing surface of each dyke, micrometric means `:for adjusting the angular element on the dyke, clamping means for holding each angular element in adjusted position, flexible packing between the under side of each angular element and the floor of the fountain, and a metering surface on each angular element obliquely adjacent to the web but not in contact therewith.

4. Means for controlling the leakage of liquid from the ends of the fountain for the coating composition in a coating machine having a resilient moving bed supporting the web of material to be coated, a floor for the lower part of the fountain to form a stock for a stationary elastic trailing blade and dykes for limiting the A width of the fountain, comprising a stationary elastic trailing blade of less length than the distance between the outer edges of the dykes mounted on the floor of the fountain, an angular element resting, on the floor of the fountain in proximity to each facing surface of the dykes,

a 'screwedl supporting stem for each element, an

'angle bracket on each dyke with a hole to receive the stem, a rst spherical assembly on each stem above the bracket, a second spherical as'- sembly on each stem below the bracket, a rst clamping nut on each screwed stem above the rst spherical assembly, a second clamping nut on each screwed stem below the second spherical assembly, flexible packing between the under side of each angular element and the floor of the fountain and a metering surface on each angular element obliquely adjacent to the web with the points of the surfaces nearest to the ends of the blade closest to the web but not in contact therewith.

5 Means for controlling the leakage of liquid from theends of the fountain for the coating composition in a coating machine having a resilient moving bed supporting the web of material to be coated, a floor for the lower part of the fountain to form a stock for a stationary elastic trailing blade and dykes for limiting the width of the fountain comprising a stationary elastic trailing blade of less length than the distance between the outer edges of the dykes mounted on the oor of the fountain, an angular element resting on the floor of the fountain in proximity to` each facing surface of the dykes, a screwed supporting tubular stem for each element, an

inator valve in the upper part of each stem, a downwardlyA opening cavity in each element, a flexible chamber in each cavity jointed to the tubular stemsadapted to be inated into jointing coaction with' the floor of the fountain, an angle bracket on each dyke, with a hole to receive the stem, spherical assemblies on each stem above and below the bracket, aflrst clamping nut on each stern above the upper spherical assembly. a second clamping nut oneach stem below the lower spherical assembly, and a meteringvsurface on each angular element obliquelyl adjacent to the web with the pointsy of the surfaces nearest to the ends of the blade. closest toA but. not in contact with. the web.

6. In means for controlling the leakage of liquid asclaimed in. claim 1 the arrangement'of the meteringV surfaces on the angular, elements obliquely to the surface of the web with the corners nearest to the ends of the blade closest to the surface of the web.

7. In means for controlling thel leakage of liquid as claimed in vclaim 1 the arrangement of a layer of flexible jointing materialv on the under surface of the angularelement that rests on the oor of the fountain.

ARTHUR RONALD TRIST.

No referencescited. 

